Field
This application generally relates to infusion packages intended for infusion, dissolution, or brewing of prepared raw materials contained within the packages. The packages are of the type that are immersed in an extracting liquid, especially infusion tea packages that are immersed in water.
Prior Art
Previously, it has been found that infusion of the contents of a tea package in hot water occurs more quickly and completely if the package does not lie at the bottom of a cup, but floats in the upper layers of the water. This could be attributed to the following: (1) the upper layers of the water have higher temperatures than the layers near the bottom, (2) the part of the package which contacts the bottom, now contacts only water and hence is fully involved in the infusion process, (3) water layers surrounding the package are stirred more freely by convection.
Several attempts were made to assure floatation of an infusion package near the surface of an extracting liquid. U.S. Pat. No. 3,809,215 to Dobry (1974) discloses an infusion package with light-weight floatation means fastened to the upper surface of the package. U.K. patent 1,436,397 to Rodrigues-Ely (1976) describes a beverage infusion device with a float proportioned to cover a major portion of water surface in a drinking vessel and attached to an infusion package. Both devices have external floatation means attached to the packages but both make the production technology of the packages more complicated and expensive, as new materials and unusual operations are involved. Moreover, the use of the packages becomes somewhat tricky, as there is always a risk that pieces of the floatation means may detach and litter the surface of the beverage.
Canadian patent 1,002,001 to Rodriques-Ely and Joannou (1976) shows an infusion filter which floats horizontally due either to floatable particles mixed with the infusible material, or to floatable disks attached to the inside of the upper wall of the filter. This eliminates the mentioned risk of the beverage littering by the floatation means pieces. Nevertheless it suffers from the following disadvantages:
(1) the material of the floatable particles and disks must be special, as it should be inert not only to water, but also to the infusible material that shares the same compartment with the floatable particles or disks, both during the storage and use of the package;
(2) the floatable particles or disks, which closely contact the infusible material during the storage, will inevitably catch some particles of the material during infusion, thus preventing their full contact with water and therefore hindering the infusion process;
(3) the production technology of the package with the floatable disks is significantly different, more complicated, and expensive in comparison with conventional technology, as it includes manufacturing of the disks and their attachment to the inner wall of the package.
To the best of my knowledge, none of the devices mentioned in these patents have been manufactured or put into practice. I believe that this is because of the mentioned disadvantages, i.e., the infusion package has the floatation means outside the package, and its technological and storage requirements are non-conventional.